In this section, simulation and numerical results are presented to
examine the impact of network parameters with STNC (e.g., the number
of relays, the relay location, Nakagami-\(m\)  fading parameters, and
power allocation) on the SER of \(U_l\) . In the figures, we consider a
practical scenario where the relays are placed at different
distances from \(D\)  and \(U_l\)  with \(c_j \ne c_i\)  and \(c_{jl} \ne c_{il}\)  for \(j \ne i\) . We set the distance between \(U_l\)  and \(D\)  as
\(d_{ld}=1\) . The cross correlations between different spread codes,
defined in (REF ), are set to be zero. We
also assume equal transmit power at each node. Further, our results
concentrate on the practical example of a highly shadowed area with
the path loss exponent as \(\alpha =3.5\)  [1]}. In the
figures, the exact SER for \(M\) -PSK is evaluated by substituting
(REF ), (REF ), and () into (REF ), and the exact SER for \(M\) -QAM
is evaluated by substituting (REF ), (), and (REF ) into (). The asymptotic SER for \(M\) -PSK and \(M\) -QAM is calculated
from (REF ) and (), respectively.
